Oxygen pressure leaching is the strengthening leaching process of zinc smelting, and the zinc leaching rate and recovery rate of the oxygen pressure leaching process are the highest. The conventional method and high temperature and high acid method should be used to roast the zinc sulfide concentrate, and the SO_2 flue gas is produced in the production process, and the acid wastewater should be treated. The oxygen pressure leaching process produces the elemental sulfur and does not release the SO_2 flue gas. Because of the oxygen rich high pressure high temperature high acid smelting environment, the oxygen pressure leaching high pressure on the equipment is higher. This paper describes the corrosion and scour damage of the casing during the process of reducing temperature and pressure, and through pre flashing casing, as well as the production practice of improving material and structure.